Layer 2 LTM cluster setup in 11.4.x

It's my understanding that that was all unnecessary. You should be able to create the trust via the management interfaces. Still, a HA VLAN would be good so you can ConfigSync (this can't be done via the mgmt interface). Seeing as you'll use a HA VLAN you probably shouldn't use serial failover and should rely on network instead.

So, I think it should look like this;

1) Just keep the HA VLAN, use 'dummy' addressing

2) Cable this via the same switches as the other VLANs but different interfaces (so it'll cause a failover if a switch fails)

3) Enable VLAN fail-safe on all VLANs

4) Configure ConfigSync and network failover on the HA VLAN only

5) Don't use the serial cable

6) Take a look at the System Fail-safe feature too

Any issues or questions, let me know.